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James Turner
Verified Expert in Engineering
Software Engineer and Developer
Derry, NH, United States
Toptal member since October 6, 2025
Bio
James has over 45 years of professional software development experience, starting with Lisp machines and continuing through the latest in iOS mobile and Java/Kotlin back-end development. He has excellent communication skills and has written three books on software development. James has also published for outlets such as WIRED, Linux Journal, IEEE Spectrum, and the Christian Science Monitor.
Portfolio
Flow
Java, Kotlin, iOS, SwiftUI, Swift, ArcGIS, YAML, Core Location
Mark43
SwiftUI, Swift, iOS, CarPlay, TestFlight, GitHub Actions, Core Location
The Weather Company
SwiftUI, UIKit, Swift, Objective-C, Core Data, Java, Apache Tomcat, MySQL...
Experience
- Java - 20 years
- SQL - 20 years
- Software Engineering - 20 years
- iOS - 15 years
- Core Location - 10 years
- Core Data - 7 years
- SwiftUI - 5 years
- Swift - 5 years
Preferred Environment
iOS, SwiftUI, Java, Kotlin, Linux, CI/CD Pipelines, Swift, Apache Maven, Gradle, SQL
The most amazing...
...The best feature I've worked on is a vertical profile turbulence view for The Weather Company's Pilotbrief app, which is patented and used by most US airlines.
Work Experience
Senior iOS Engineer
2024 - 2025
Flow
- Developed a functionality for the Flow iOS Guest and Host applications using SwiftUI and UIKit. Translated Figma design specifications into iOS UI/UX implementation.
- Interviewed iOS engineers and developed interview coding challenges.
- Architected the effort to capture geopositioning data for Flow properties down to the appliance level. Developed a methodology using ArcGIS and customer Java/Kotlin tooling to turn PDF blueprints into georeferenced object data.
- Prototyped and delivered a Raspberry Pi-based geobeacon system using BLE, which allowed front-desk staff to greet guests with iPhones as they came into the lobby.
- Prototyped a Raspberry Pi-based "treasure box" system that allowed residents to get credits for attending community events.
Technologies: Java, Kotlin, iOS, SwiftUI, Swift, ArcGIS, YAML, Core Location
Staff iOS Engineer
2022 - 2024
Mark43
- Worked on a green-field project to create a computer-aid-dispatch mobile application for first responders, using SwiftUI.
- Pioneered and championed the use of OpenAPI throughout the company to promote contract-driven development.
- Leveraged SwiftUI with Combine to create reactive model-driven user interfaces that were also form-factor responsive.
- Developed tools to easily generate Core Data schemas from OpenAPI data models.
- Implemented WebSockets communication with Java-based back-end services.
- Created a map screen based on the ESRI map toolkit that could display thousands of units and events on the map in real time with constant updates.
- Collaborated with the UI/UX team to refine app design, creating pixel-perfect yet responsive screens.
- Helped maintain TestFlight and GitHub Actions configurations using Fastlane.
- Integrated with Firebase for crash analysis and analytics.
- Developed a CarPlay integration MVP, allowing officers to use their in-dash display to view and respond to events.
Technologies: SwiftUI, Swift, iOS, CarPlay, TestFlight, GitHub Actions, Core Location
iOS Team Lead
2016 - 2022
The Weather Company
- Acted as a core contributor and team lead for an existing mature flight-deck weather application for commercial pilots, leveraging Swift 5 best practices, SwiftUI, and UIKit.
- Received an IBM award for outstanding technical contribution in relation to my initiative to reduce bandwidth consumption in airline cockpits.
- Rewrote a flight route parser using C++, ported it to run under iOS/Swift via bridging code.
- Developed a vertical profile capability, which led to a patent.
- Worked as a liaison for development efforts between the iOS team and server teams, implementing back-end functionalities.
- Implemented support tools in Java using Spring Boot to interact with an Amazon S3 (AWS S3) environment, creating test data for development testing and QA. Stood up servers in EC2 using Docker.
- Maintained a Jenkins CI/CD server for XCode and Maven-based builds. Integrated with Fastlane for deployment to the Apple App Store for TestFlight.
- Screened over 200 college candidates and designed a programming problem that was used IBM-wide for screening.
- Applied my personal experience in aviation, mentoring team members in technical details of flight planning and other flight-related topics.
Technologies: SwiftUI, UIKit, Swift, Objective-C, Core Data, Java, Apache Tomcat, MySQL, Fastlane, C++, Spring Boot, Docker, Core Location
Chief Architect
2014 - 2016
Online Convergence Corporation
- Architected a multi-tier, multi-platform social gaming application.
- Designed and implemented a mobile social slot machine game, using iOS and Android frameworks. Handled the UIKit iOS implementation and supervised Android developers.
- Worked with the design team to ensure a pixel-perfect look and feel.
- Developed a scalable fault-tolerant back end capable of servicing 100+ requests per second using Amazon EC2, DynamoDB, RDS/Aurora, S3, CloudFront, and Route 53.
- Integrated 3rd-party advertising and fulfillment trackers into mobile applications. Integrated Facebook and Fabric support.
Technologies: iOS, UIKit, Core Data, AWS ELB, Amazon S3 (AWS S3), Elastic Cloud, MySQL, Amazon DynamoDB, Java, Docker, Apache Maven
Senior Software Engineer
2006 - 2013
Kronos Incorporated
- Acted as the lead iOS developer and architect on the industry award-winning Kronos Mobile and Kronos Tablet projects. Did the initial implantation of the UIKIt-based iOS application.
- Ensured that products met service requirements for performance, and adhered to Apple application guidelines.
- Worked on an extensible platform for a next-generation timekeeping terminal, based on Linux and Java. Ensured that the platform secured private employee data and that core application functionality could not be subverted.
- Collaborated with the product owner and UI/UX designers to determine functionality and the look and feel of products.
- Performed initial architecture design of a next-generation terminal product, including rapid prototyping using Beagle boards and various Java implementations.
- Worked as a member of Kronos Labs, investigating future technologies the company might be able to use to improve the reliability of code or the productivity of developers.
Technologies: Java, iOS, Linux, C, XML, SQL, UIKit, Core Data
Experience
Pilotbrief
https://www.weathercompany.com/aviation/pilotbrief/An iPad app used by almost all major US airlines in the cockpit, allowing them to visualize weather conditions, read their NOTAMs, and sign off on their flight releases. I contributed to all aspects of the application, but most notably was responsible for the Vertical Profile feature, which allows pilots to visualize a vertical slice through the atmosphere along their entire route of flight. This work resulted in the issuance of a patent with me as the primary inventor.
Spin to Win Slots
https://apps.apple.com/us/app/spintowin-slots-sweepstakes/id830842541An iOS/Android game that allows users to win real money. I was the chief architect of the solution, was solely responsible for the iOS application, and supervised the developers working on the Android side. I wrote and maintained the Java server-side application, which easily handled hundreds of concurrent spins per second.
Education
1980 - 1984
Bachelor's Degree in Computer Science
Hampshire College - Amherst, MA, USA
Skills
Libraries/APIs
ArcGIS
Tools
Apache Maven, TestFlight, Apache Tomcat, AWS ELB, Gradle, Fastlane
Languages
Java, Swift, Lisp, SQL, YAML, Objective-C, Kotlin, APL, C, C++, XML
Frameworks
SwiftUI, UIKit, Core Data, Core Location, Spring Boot
Platforms
iOS, Linux, Docker
Storage
MySQL, Amazon S3 (AWS S3), Amazon DynamoDB
Other
CI/CD Pipelines, Software Engineering, CarPlay, GitHub Actions, Elastic Cloud, Computer Science
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